Septic soil in Kane County, IL, by the numbers

Very limited

Soil across 97.9% of Kane County, IL rates "Very limited" in USDA's septic-absorption-field interpretation. A standard gravity system routinely fails on ground like this; the same share of the county falls in USDA's worst absorption-field bucket outright. Kane County covers 519.361 square miles and counts 520,997 residents.

This is a county figure, not a parcel figure

Nothing about Kane County, IL's SSURGO figure applies to a specific address - it's a county-wide average. A site-specific perc test, usually $750-$1,850, is what a health department will actually require before permitting a lot in Kane County.

System cost, conventional vs. engineered

Given Kane County's rating, plan for the engineered-system range rather than the conventional one. The engineered-system range, $10,000-$40,000 (mound or aerobic treatment), is the more realistic number to plan around, against $3,000-$8,000 for a conventional system on the rare lot that passes.

How Kane County, IL compares

Nationally, Kane County, IL is the 257-most-constrained of 3,058 rated counties for septic soil. Within Illinois alone it ranks 13 of 101.

Before you act on this

How this rating is built, and its real limits · Conventional vs. engineered septic systems